Start a pipeline run

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is covered. The description adds that all body fields are optional and that the response carries a pipelineRunId for polling, which is useful, but it omits auth/scope behavior, idempotency, and side effects of an actual run.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, front-loaded with purpose, then field guidance, then the response contract. Every sentence adds value and there is no filler, though the field-routing sentence is dense.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be detailed, and the description appropriately limits itself to noting pipelineRunId for polling. For a 3-parameter trigger tool with a nested body, the routing guidance is sufficient, but several body fields and any precondition on pipeline state remain undocumented.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 67% schema coverage, the description compensates by explaining the semantics of the key optional groups: branch/commit for Git-backed pipelines, versionNumber for Orchestra-backed published versions, and runInputs for pipeline input values. It leaves ciRunId, taskIds, retryFromFailed, environment, and environmentOverrides unexplained, so it is helpful but not exhaustive.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ("Start a pipeline run") and identifies the two ways the pipeline can be addressed, which cleanly separates it from siblings like cancel_pipeline_run, validate_pipeline, and update_pipeline. It does not explicitly name a sibling, so it falls just short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the field-routing guidance (branch/commit for Git-backed, versionNumber for published versions, runInputs for inputs), which tells the agent how to invoke it. However, it never says when to prefer this tool over alternatives or what preconditions exist (e.g., pipeline must be unpaused), so guidance is incomplete.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.